Recently, many efforts have been made to develop such a technology as Bluetooth, WPAN (wireless personal area network) and the like for exchanging audio/video data between devices via a wireless network between the relatively small number of digital devices in a limited spate such as a house, a small-size work place, etc.
WPAN is usable in exchanging information between the relatively small number of digital devices in relatively close distance and enables the digital devices to perform low-power and low-cost communication in-between.
IEEE 802.15.3 [Wireless Medium Access Control (MAC) and Physical Layer (PHY) Specifications for High Rate Wireless Personal Area Networks (WPANs)], which is approved on Jun. 12, 2003, defines specifications about medium access layer (MAC) and physical layer (PHY) of high-rate WPAN.
If communication is carried out through wireless technology, it is able to remove wires including cables and the like to connect the devices together. And, it is also able to exchange data information directly between devices through device-to-device wireless network communication.
And, all devices including a computer, a personal digital assistant (PDA), a notebook computer, a digital TV, a camcorder, a digital camera, a printer, a microphone, a speaker, a headset, a barcode reader, a display, a mobile phone and the like are usable in performing communication on the network.
If a power equal to that used in performing communication is consumed while devices constructing a wireless network stop performing wireless communication, the power is consumed of no use to reduce efficiency of a wireless network communication system. So, the demand for a power management method for reducing a required power quantity in the course of not performing data transmission and/or reception between devices rises.
Specifically, since a device operable by a battery power source has a limited usable power quantity, a method of elongating a communication time by reducing power consumption is required.